Integrated circuit (IC) devices of a system are typically interfaced using input and output circuits. The output circuit of one IC device is used to drive the input circuit of another IC device, which is usually dominated by capacitance. The connection between the IC devices can consist of bondwires and/or short (<<λ/4) transmission lines, which are usually inductive. For such an interface the following equations apply:             R      D        ≅          1              2        ⁢        π        ⁢                                   ⁢                  BWC          L                      ,            R      D        ⁢          <<                        L                      C            L                                ,            R      L        >>                                        L                          C              L                                      ⁢                                   ⁢        and        ⁢                                   ⁢                  f          res                    ≅              1                  2          ⁢          π          ⁢                                    LC              L                                            ,where RD is the resistance of the output circuit, BW is the bandwidth, CL is the load capacitance of the input circuit, RL is the load resistance of the input circuit, L is the inductance of the device-to-device connection and ƒres is the LC-resonance frequency.
In many wideband applications, a flat or very low voltage peaking frequency response with maximum bandwidth is desired. However, the interfaced IC devices will have a LC-resonance at ƒres. Even though the system bandwidth may be determined by the output circuit and be smaller than ƒres, the transfer function of the overall system can suffer from considerable peaking due to the inductive resonance of the interface. The amount of peaking is determined by the quality factor Q, which can be expressed as:       Q    ∼                  1                  (                                    1              /                              Q                L                                      +                          1              /                              Q                C                                              )                    ⁢                           ⁢      with      ⁢                           ⁢              Q        L              =                              ω          ⁢                                           ⁢          L                          R          D                    ⁢                           ⁢      and      ⁢                           ⁢              Q        C              =                            R          L                ·        ω            ⁢                           ⁢                        C          L                .            
Existing methods of high speed device-to-device connections to control peaking involve selecting RD and RL such that RL, RD≅ZL, where ZL=√{square root over (L/CL)}, based on the termination of transmission lines. However, the use of these methods reduces the achievable bandwidth if RD is increased, or reduces the signal amplitude if RL is decreased to ZL. Furthermore, RD, RL and CL are subject to process variations of integrated circuit technology. Thus, the selecting of RD and RL to control peaking with predictable results is a difficult task due to the process variations.
In light of these concerns, what is needed is a multi-device system and method for controlling voltage peaking of an output signal transmitted between interfaced IC devices without significantly reducing the achievable bandwidth and/or the signal amplitude, while taking into consideration process variations.